Sorting an array list of intervals?

Question

I have a set of intervals S contained in an array list. How can I sort those arrays based on the left or right end-points?

For instance, if I had the following intervals [1,3],[1,2],[2,5],[3,3] how can I sort them based on their left end-points?

I am aware of the different sorting algorithms like sequential sort, insertion sort and merge sort, but I'm clueless on how to sort a set of intervals.

Any help or hints to guide me in the right direction will be appreciated.

Answer 1

尝试基数排序，如果所有值都是一位数，它会帮助你，它很容易实现。

Answer 2

Try with this command

intervals.sort((i1, i2) -> Integer.compare(i1.start, i2.start));

Hopefully you will get it correct based on starting points or if you want to sort based on end points just compare (i1.end,i2.end) .